Pornography websites attract millions of users each month, reportedly more than either CNN, Amazon or Twitter. A recent phenomenon, “tube” sites, is competing with the traditional porn industry by providing large amounts of free pornographic content from amateur or pirated videos. Because the sites are easy to access through computers or cell phones, children can view hard-core, often violent, content that gives them a warped view of sex, say parents and some social scientists. Critics describe a porn-induced public health crisis that is contributing to divorce and normalizing sexual violence against women. But with rape, divorce and teen pregnancy at historic lows, other social scientists and porn defenders say these concerns are overblown and lack evidence of harm to society. Meanwhile, civil liberties activists criticize some child advocates’ solutions, such as requiring websites to verify the age of users, as violating adult users’ free-speech and privacy rights. So far, the Supreme Court has agreed, striking down previous congressional efforts to restrict internet access.